Slain prison escapee Richard Matt will be buried in an unmarked grave upstate — because none of his relatives has claimed his body, officials said Wednesday.

The convicted murderer was no longer officially a ward of the state when he was fatally shot by a fed on Friday, so his corpse is now the responsibility of Franklin County, where he made his last stand, said Brian Langdon, one of the county’s coroners.

A Buffalo TV station reported that Matt’s son, Nicholas Harris, was planning to claim the body, but he missed a mid-Tuesday deadline, according to a spokeswoman for the hospital where it was sent after an autopsy in Albany.